Rhombic dodecahedral structure composed of pleated sheets.
 

The file RhmbidecPeptide.pdf shows how three chains of two strands
each can sheet-join to form three pleated sheets which define the
faces of a rhombic dodecahedron at a threefold vertex. The structure
is similar to the "beta annulus" noted in the TBS Virus in 1978 by
Harrison et al. Two beta annuluses can be linked by a common chain. A
network of these can define a rhombic dodecahedral peptide. The file
can be downloaded using the "Files for sharing" link on the website
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